The sister of Sean Rigg has vowed to continue her fight for justice after a police misconduct panel dismissed allegations against five officers involved in his fatal detention.

Marcia Rigg-Samuel has fought an 11-year battle since her brother, a 40-year-old with schizophrenia, died after being restrained by Metropolitan Police officers.

But on Friday (March 1) a disciplinary panel dismissed all allegations against police constables Andrew Birks, Richard Glasson, Matthew Forward, Mark Harratt and Sergeant Paul White.

READ: Claims that officers lied about Sean Rigg in custody case are dropped

The panel, led by Commander Julian Bennett, dismissed claims that any of the officers instigated a cover-up after Mr Rigg's death, despite accepting they had at times given incorrect statements.

He ruled these were "not deliberate lies" and attributed them to the passage of time and false memories being created.

The chairman also ruled the officers did not restrain Mr Rigg inappropriately, did not fail to recognise he was suffering with mental health problems and did not fail to ensure he received adequate medical care when it became clear he was seriously ill.

Addressing journalists outside the hearing, Ms Rigg-Samuel clutched a copy of the inquest report that found the officers had used "unsuitable" force and that the way he was restrained "more than minimally" contributed to his death.

"Today's decision and the fact that somebody can be restrained in the prone position for seven minutes has given the officers a licence to kill," she said.

"It may be the end of the legal proceedings but it's not the end as far as me and my family are concerned. The truth will [come] out."

Her lawyer Daniel Machover said the panel's conclusion that holding Mr Rigg in the prone position for seven minutes was not excessive is "chilling and dangerous".

READ: Family forced to relive Sean Rigg's death as they fought for accountability

But Scotland Yard's head of professionalism Assistant Commissioner Helen Ball thanked the officers, noting they had "been the subject of significant and protracted scrutiny" after being sent "into the most challenging of situations".

And the Metropolitan Police Federation said the result means "our colleagues can finally get on with their careers and lives having been investigated for this incident for the past 11 years".

A statement criticised the former police watchdog, the Independent Police Complaints Commission, for causing the excessive delay.

Its successor, the Independent Office for Police Conduct (IOPC), said it regrets delays and that investigators are continuing to finish a small number of cases left over by its predecessor.

The investigations have taken so long that Mr Birks is now an ordained priest, although he is still paid a police salary because he was denied permission to resign while proceedings were ongoing.

The Police Federation, which represents officers from the rank of constable to chief inspector, has called for a year time limit for disciplinary proceedings in the wake of a number of cases that have taken several years to conclude.

Mr Rigg, a physically fit musician, died at Brixton police station in August 2008, and it was four years before the full inquest into his death took place.

It was another four years before prosecutors finally confirmed that no criminal charges would be brought over his death, bar one count of perjury against Mr White, who was later cleared.

The officers involved will now be allowed to resume full duties, or resign.

The IOPC has come under fire for delays in the case, and been accused of a failure with its initial investigation to get to grips with basic issues.